Hourly global solar radiation for Kuala Terengganu of Malaysia

Abstract

In this paper, six selected empirical models were used to estimate the hourly global solar radiation from the daily global radiation in Kuala Terengganu on the east coast of Malaysia. The purpose is to determine the most accurate models to be used for estimating the hourly global solar radiation. The measured hourly global solar radiation data used for the validation of selected models were obtained from the Malaysian Meteorology Department and University Malaysia Terengganu Renewable Energy Station for the period of 2004–2008. In order to indicate the performance of the models, the statistical test methods of the normalized mean bias error, normalized root mean square error, correlation coefficient and t- statistical test were used. The hourly global solar radiation values were calculated by using six models and the results were compared with corresponding measured data. All the models fit the data adequately and can be used to estimate the hourly global solar radiation. This study finds that the Collares-Pereira and Rabl model performed better than other models. Therefore the Collares-Pereira and Rabl model is recommended to estimate the hourly global radiations for Kuala Terengganu and elsewhere with similar climatic conditions.